US2603949A

US2603949A - Combustion chamber with diverse air paths and vortices producing vanes therein for jet propulsion or gas turbine power plants

Info

Publication number: US2603949A
Application number: US788585A
Authority: US
Inventors: Edmund D Brown
Original assignee: United Aircraft Corp
Current assignee: Raytheon Technologies Corp
Priority date: 1947-11-28
Filing date: 1947-11-28
Publication date: 1952-07-22
Anticipated expiration: 1969-07-22

Description

E. D. BROWN COMBUSTION CHAMBER WITH DIVERSE AIR PATHS AND July 22, 1952 VORTICES PRODUCING VANES THEREIN FOR JET PROPULSION OR GAS TURBINE POWER PLANTS 2 SHEETSSHEET 1 Filed Nov. 2 194'? lllllll llll ll.

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Mm mm Q 4/ W m K I y m hi 1 i Q ATTORNEY July 22, 1952 E. D. BROWN 2,603,949

' COMBUSTION.CHAMBER WITH DIVERSE AIR PATHS AND VOR'I ICES PRODUCING VANES THEREIN FOR JET PROPULSION 0R GAS TURBINE POWER PLANTS Filed Nov. 28, 1947 2 Si-iEETS-SHEET 2 ATTORNEY tially cylindrical portion with a number of inwardly extending vanes 54 preferably of air-foil shape in cross-section. The inner ends of these vanes are spaced from the shell and the vanes preferably have .a substantial/angle of attack with respect to the fluidflowing through the passage thereby creating considerable lift and caus- 1 ing strong tip vortices trailing downstream from her thereby creating a considerable lift resulting i in a series of strong tip vortices.

The outer row of vanes 34 may be arranged with the angle of attack reversed with respect to the inner row of vanes 33, or the opposite rows of vanes may be at the same angle of attack so, that the resulting vortices will beopposite directions as shown in Fig. 3.

Downstream from the trailing ends of the shields 24 and 26, the ducts 20 and 22 have one or more sets of vanes 38 and 40 projecting into the combustion chamber and also preferably of airfoil shape in cross-section. The inner ends of the vanes are spacedfrom the walls of the .combustion chamberand preferably substantially on the mutual boundary between the secondaryair which passes around the outside of theshields 24 and 26 and the gas resulting from the combustion process which occurs in the annular passage 28.:

vanes the secondary vanes 38 and 40 may have opposite angles of attack so that the vortices are in oppositedirections or may have similar angles of attack asshown in Fig. 3 so that the vortices resulting from the inner and outer vanes are in the same direction and thus are in opposition to each other. Preferably the secondary vanes 38 and 46 are spaced between the primary vanes 34 and 36, asbest shown in Fig. 3, and also as.

shown, the outer primary vanes 34 and the outer secondary vanes 38 preferably have similar angles of attack, although it will be apparent thatunder certain circumstances the arrangement of.

these vanes at opposite angles of attack would'be advantageous. i

The invention is equally applicable to theround or can type ofcombustion chamber, As

shown in Figs. 4 and 5, the combustion chamber insteadof being annular in construction} asabove described, is round and a number of combustion chambers are arranged in a ring around the shaftof the power plant.- In these figures the combustion chamber is in the form ofa sub-' stantially circular duct 42 forming the wall of the combustion chamber and this duct has a substantially circular shell 44 within and spaced from the walls of the duct and forming the'passage 46 within which the primary air and the fuel are burned. The shell 44 consists of a substantially conical portion 48,'the inlet end of which substantially surrounds the fuel nozzle 50; The' larger-end of the conical section 48 which is the downstream end connects with a substantially cylindrical portion 52 preferably located within a part of-the duct 42 which is also substantially cylindrical. The conical portion 48 has airpassages 53 by which primary air enters the passage 46 to, mix withfuel from nozzle 50. I 1

Toassure proper; mixing, the shell. is provided adjacent the upstream end of its substanthe vanes to assure thorough mixing of the fuel and. primary air.

After combustion is substantially completed, the combustion products from the passage 46 are caused to mix with the secondary air flowing I around the shell by a second set of vanes 56 projecting inwardly from the duct 42 and with the 'betw'een'the secondary air and the products of the same so that the secondary vortices follow the primary vortices. It will be apparent that under certain'conditions it will be advantageous to reverse the angle of attack of the second set of vanes thereby causing the secondary vortices to rotate in a direction opposite to that of the primary vortices.-

With respect to Fig. 6 the combustion chamber maybe so arranged that the vanes for mixing the secondary air withthe products of combustion are located directly at the end of the passage in which combustion takes place. As shown,

the combustion chamber'is' in the form of 'a substantially circular duct 58 forming the wall of. the combustion chamber and surrounding a substantially circular shell 60 within and spaced from the walls of the duct. The shell forms the passage 62 within which the primary air and fuel are burned. The fuel may, for example, be delivered through a nozzle 64 to a cup 66 located adjacent to the inlet end of the passage 62. At the inlet end of the shell 60 are a series of vanes 68, extending inwardly fromthe shell, and

with the inner. ends of. the vanes preferably in alignment'with thebrimof the 'cup so that the: flow of air. into the passage past the vanes' 68 will." create strong tip'vortices which will be lo cated substantiallyv on the .mutual'boundarybetween the air entering thechamber. and the fuel discharging from :thet cup; .The leading edges of. thevanes' support the brim'of the cup and the vanes extend downstream therefrom. The effective part of'thevanes is thus beyond the end of thecup in the direction of. gas flow.v r;

The secondary air passes through the space. between the shell 60 and .the duct 58 to the.

downstream end of the shell 60 where apart of the secondary airenters the-space in which combustion is taking place by 'fiowing'jiover a series of vanes 10, the leading edges o'f'which' are substantially in line with the end of the :shell 60 and theinner ends'of which are sub- I These vanes 10 may be supported from the outer duct stantially coincident withthe shell 60.

58 by ribs 12- which also function to support a second shell 14- -which extends downstream-from the 'vanes'lo to an additional row' of vanes 16$ This row: of v'anes' extends between the duct 58 and l the: downstream" end (if-the shell- 11;. The

vanes TB ararranged so thatthe inner ends thereofcoincide substantially'iwi tln the shell; 'I'hese vanes may be-arranged: with the same angle of attack as the-row of vanesilll-or they: may be ';reversed as shown, since byreversal of the vanes, i't is possible to create agreater tur bulen'ce; The e'ifective part of the vanesJO' and- 16 are located beyond the 'ends of the Shields 60 and 14 respectively, inthe direction 1 of gas flow so thatthey may f-unction" ta'pro'duce the tip vortices i n-the gas flowing over-the vanes.

Although in the arrangements shown; e11 of i the vanes of i anyone set are arranged with the.-

same angle-of attack,= it will be apparentthat adj 'acent vanesin--any *setmay be arranged with opposite {angles of-"-'- attack; as it i is found that s'uch narrangement-produces more 1 adequate mixing of the primary air "and the -fuelto? there= byshortening' the space within whichthe combustion takes place. 'I-he'use: of oppositely-ar ranged vanes in improving' thei-fl'ow of fluid-in:

a ductdsclair-n'edi-n the copending application of Bruynes, SerialNo. 769,042, filed August 16, 1947, now Patent No: 2,558,816;-

;It is to:v be: understood that. the invention is not limited to the specific embodiment'herein illustrated ,and, described, but may be used in other ways Without departure from its spirit as defined by the following claims. """'1 l. .s

v thechamberY'a-shell wit said duct? and form-ing -apassage-within which -"the primary airf and -fuel-- are -mixe'd' and burned; the

secondary 'air flowing around said shell} means I for creating vortices within said shell at points spaced from the wall thereof to mix the fuel and air with the centerline of the vortices substantially parallel to the axis of the duct, and other means spaced from and beyond the discharge end of said shell for creating additional vortices for mixing the fluid from the shell with the secondary air with the centerlines of the vortices substantially parallel to the axis of the duct.

2. In a combustion chamber, a duct forming the wall of the chamber, a shell within said duct and forming a passage within which the primary air and fuel are mixed and burned, the secondary air flowing around said shell, means for creating vortices in said shell at points spaced from the wall thereof to mix the fuel and air, and other means spaced-from and beyond the discharge end of said shell for creating additional vortices for mixing the fluid from the shell with the secondary air, said other means being arranged.

to produce vortices having the same direction of rotation as the first vortices.

3. In a combustion chamber, a duct forming the wall of the chamber, a shell within said duct and forming a passage within which the primary air and fuel are mixed and burned, the secondary air flowing around said shell, means for creating vortices in said shell at points spaced from the wall thereof to mix the fuel and air, and other means spaced from and beyond the discharge end of said shell for creating additional vortices for mixing the fluid from the shell with the secondary air, said other means being arranged to produce vortices having the opposite direction of rotation to that of the first vortices.

4. In a combustion chamber, a duct forming the wall of the chamber, a shell within said duct and forming a passage within which they l 6} In a combustion chamber, the-wallof' th'e chamber,

duct and forming a passage -with-i n which the 61 secondary ai r -fiowing around said shell; and vanes extending into" said chamben -with one end" of each vane spaced from the wa'l-l thereof,

the vane's being' arranged at an angle' -to the flow for creating additionalyortice's, the-free ends' of said other vanes being substantially :in

line with" the shell so that the vortices WilI haVe their axis substantially in linewith :the shell. 5. In a-combu'stion chamber, a duct forming the wall of thechamber, a shell within said duct and forming a'passage within which the primary airand fuel are mixedand burned, the secondary airflowing around said shell, and vanes extending into said ch'amb'erfone end o'f each'vane being I spaced from the wall thereof, the vanes being:

arranged at an angle to the flow of fluid-through said duct vortices-for mixing the fuel and air in the chambe'r,'and other vanes positionedin' said duct-be yond'th'edi'scharge end of 'the s'helland arranged at an angle to the flow for creating additional: vortices,- with the first set-of vanes-in 'aligwith the second set of vanes primary air and fuel are mixedand burned =the secondary air flowingaround-said shell-and-vanesextending into said chamber, one-'end of each.

, vane being spaced fromthe wall-'thereofi-fthe vanes being arranged at an angle to theflOW' of fluid through said duct so that the-ends theredf' -will create vortices for mixing the fuel and air in the chamber, and other vanes positioned in said duct beyond the discharged end of the shell and arranged at an angle to the flow for creating additional vortices, with both sets of vanes having approximately the same angular arrangement in relation to the direction of flow.

7. In an annular combustion chamber, inner and outer ducts forming the inner and outer walls of the annular chamber, inner and outer shields within said chamber and spaced from said ducts to define, between said shields, an annular passage within which the primary air and fuel are mixed and burned, and a number of vanes positioned within the passage with one end of each of the. vanes spaced from the shields andarrangedto cause trailing vortices to improve the air and fuel are mixed and burned, and a number of vanes positioned within the passage with one end of each of the vanes spaced from the shields to cause trailing vortices to form as the fluid flows through the passage.

9. In an annular combustion chamber, inner and outer ducts forming the inner and outer walls of the annular chamber, inner and outer shields within said chamber and spaced from said ducts to define, between said shields, an annular passage within which the primary air and fuel are-mixed and burned, and a number of vanes extending into said passage from one of said walls with one end of each of the vanes spaced from the shields to cause trailing vortices to improve the mixing of air and fuel.

, 10. In an annular combustion chamber, inner so thatthe ends thereof will-create ent ai -duct forming. a? shell within said and outer ducts forming the inner and outer walls of the annular chamber, inner, and outer shields within said chamber and spaced from said ducts to define, between said shields, an annular passage within which the, primary air and fuel are mixed and rburned and a, number, of vanes extending into said passage from each of said walls, with one end of each of the vanes spaced from the shields to cause trailing vortices to improve the mixing of air and fuel.

11. In an annular combustion chamber, inner and outer ducts forming the inner and outer walls of the annular chamber, inner and outer shields within said chamber and spaced from said ducts to define, between said shields, an annular passage within which the primary air and fuel are mixed and burned, and a number of vanes extending into said passagefrom each of said walls, with the vanes on one. wall arranged at an angle opposite to the vanes on the other wall. 3

12. In an annular combustion chamber, inner and outer ducts forming the inner and outer wallsof the annular chamber, inner and outer shields within said chamber and spaced from said ducts to define, between said shields, an annular passage within which the primary air and fuel are mixed and burned, and a number of vanes extending into said passage from one of said walls with one end of each of the vanes spaced from the shields .to cause trailing vortices to improve the mixing of air and fuel, and additional vanes extending into the chamber beyond the ends of the shields to cause mixing of the fluid in the passage with the secondary air in the space between either shield and the adjacent duct. r

13. In a combustion chamber, a duct forming the wall of the chambena shell within said duct andforming. a passage within'which the primary air and fuel are, mixed and-burned, the secondary air flowing aroundsaid shell, means :for, creating tip vortices in said shellv adjacent the inlet end at, points spaced fromthe wall thereof to mix thefueland air,- and other means in the form of vanes at the discharge end of said shell for creating additional vortices, the last vortices being formed with, their axes substantially coincident with the shell. i I Y 14. In a combustionchamber, a .duct forming the wall of the chamber, a shell within said duct and forming a passage within which the primary air and fuel are mixed and burned, the secondary air flowing around said shell; means for creating tip vortices in said shell adjacent the inlet end;

atpoints spaced fromithewall thereof to mix the, fuel and air, a second means at the discharge end of; said shell for-creating vortices with their axes substantiallypoincident with the shell, and vanes spaced downstream from said second means for causing additional tip vortices. EDMUND-,ILBROWN.

REFEnENcEscITED, The following references are of record in the file of this patent: I 1

UNITED s'rn rns PATENTS Number Name Date 7 1,613,803 Burg Feb. 272, 1927 1,910,735 Zikesch lVIay 23, 1933 2,396,068- YOllnEa h Man 5, 1946 2,417,445 Pinkel Mar.18 1 9 4 '7 2,4:46359 Peterson July 27,4948

Birmann Aug. 2, 1949"